The present invention relates to the field of contamination detection devices. More specifically, the present invention relates to a detector that detects residual hydrocarbon contamination on a surface.
Parts and equipment cleaning is an integral part of a wide range of major industries such as aerospace, electronics equipment and computer manufacture, medical equipment manufacture, chemical manufacturing, and so forth. Indeed many applications of machined parts require the utmost cleanliness in the part exterior surfaces for successful application in their intended use. In all of these industry segments, large quantities of hazardous solvents are routinely employed, and eventually find their way into a waste stream, or are emitted into the air. Two major solvent waste generating mechanisms include unnecessary overcleaning and undercleaning.
In order to minimize cleaning problems, some industries use procedures that overclean most parts in the hopes of adequately cleaning all of the parts. Unfortunately, large volumes of hazardous and volatile solvents are often wasted when overcleaning parts. Solvents are also wasted through the use of improper undercleaning procedures. That is, industrial parts that were improperly cleaned the first time, i.e., undercleaned, must be recleaned, which further generates solvent waste. The solvents wasted through the practices of overcleaning and recleaning parts exacerbate the problem of water and air pollution by cleaning solvents. To avoid such waste, industry leaders are continually seeking to use cleaning solvents in as efficient and conservative a manner as possible by improving cleaning solvents and parts cleaning procedures.
Hydrocarbon-based cleaning solvents are often used to clean the exterior surfaces of machined parts following manufacture. Improper cleaning procedures, both overcleaning and rework due to undercleaning, can result in a residual layer of hydrocarbon contamination from the cleaning solvent itself on the surface of the machined part. Residual hydrocarbon contamination can cause quality and reliability problems with the machined parts, resulting in costly, and sometimes dangerous, parts failure.
Verification techniques for detecting hydrocarbon contamination and other contaminants on machined parts are sometimes used to ensure the efficacy of cleaning procedures. Unfortunately, the verification techniques involve lengthy and error prone analytical laboratory procedures. Due to the expense and delay of such laboratory analyses, they are typically only used as spot checks of cleaning performance. This leaves open the possibility for contaminated parts escaping the quality control process, leading to expensive field failures. Moreover, since such tests have turnaround times of several days or longer, the laboratory analyses may not identify a problem until many parts have been improperly cleaned.
Accordingly, it is an advantage of the present invention that a hydrocarbon detector is provided.
It is another advantage of the present invention is that a hydrocarbon detector is provided that conveniently and cost effectively screens machined parts for hydrocarbon contamination.
It is another advantage of the present invention that a hydrocarbon detector is provided that can present real-time cleaning verification feedback in an industrial production line environment.
Yet another advantage of the present invention that a hydrocarbon detector is provided that is a handheld, self-contained unit.
The above and other advantages of the present invention are carried out in one form by a portable hydrocarbon detector for detecting a hydrocarbon presence on a surface. The detector includes a gas stream delivery element having a delivery element outlet configured to discharge a carrier gas onto the surface, the carrier gas serving to volatilize the hydrocarbon presence from the surface. The detector further includes a gas stream recovery element having a recovery element inlet configured to aspirate a sample gas formed from the carrier gas combined with the hydrocarbon presence volatilized from the surface. A hydrocarbon sensor, in fluid communication with the gas stream recovery element, detects the hydrocarbon presence in the sample gas and generates an output signal indicative of the hydrocarbon presence. An indicator is coupled to the hydrocarbon sensor for receiving the output signal and indicating the hydrocarbon presence in the sample gas.